Seepage Characteristics Analysis on Earth Dams Considering Polymer Cutoff Wall with Construction Defects

In recent years, non-water reaction polymer grouting is a new technology for anti-seepage and reinforcement that has been widely employed in anti-seepage projects. However, there is little research on the consequence of defective polymer cutoff walls affecting the seepage safety of earth dams. To analyze the influence of the number, location, and randomness of defects in the wall on seepage characteristics of the earth dam, a three-dimensional finite element model of a typical earth dam with the polymer cutoff wall is established by numerical simulation technology. The model reflects the real geometry of the polymer cutoff wall as well as the internal common construction defects-windows and uneven thickness. The results indicate that construction deficiencies, especially defect rate and thickness uniformity, have a negative effect on the actual anti-seepage performance of the polymer wall. Eventually, the seepage safety of the earth dam may be endangered due to overestimation of the actual impermeability, if only assuming the cutoff wall is intact. Therefore, the index reflecting the integrity and the impermeability of the polymer cutoff wall is proposed, and the corresponding proposals are offered based on calculation results.